Factors Related to Postoperative Pain Trajectories following Total Knee Arthroplasty: A Longitudinal Study of Patients Admitted to a Russian Orthopaedic Clinic

Table 5

Descriptive characteristics of surgery duration (minutes), tourniquet use, and postsurgical hemoglobin for five different types of knee replacement implants.

		Surgery duration; Mean (SD)	Tourniquet use; % ()	Bleeding, mL; Mean (SD)	Hemoglobin, g/L		Postoperative; length of stay; Mean (SD)
					Day 0, 20:00; Mean (SD)	Day 4; Mean (SD)
Sigma	43	93.6 (20.0)	11.6% (5)	381 (172)	107.9 (11.7)	101.4 (15.0)	9.60 (2.89)
AGC	34	87.8 (20.6)	26.5% (9)	291 (165)	108.4 (10.9)	101.0 (12.1)	8.74 (1.68)
Other implants:	23	110.7 (27.7)	30.4% (7)	343 (215)	103.7 (12.5)	93.8 (11.5)	8.91 (2.21)
LCS	14	105.4 (21.1)	50.0% (7)	318 (192)	100.4 (9.2)	91.1 (11.5)	8.29 (2.16)
Scorpio NRG	5	104.0 (5.5)	0%	470 (311)	110.0 (4.9)	99.4 (8.5)	10.80 (1.64)
NexGen	4	137.5 (49.9)^a	0%	275 (126)	107.0 (24.8)	96.5 (14.2)	8.75 (2.06)

Note. Italicized text represents the 3 types of implants grouped together as “other implants.” Implant types did not differ with respect to bleeding, length of postoperative hospital stay, creatinine values (not shown), or CRP values (not shown).
Surgery duration differed significantly by implant type (). In post hoc testing, the Sigma () and AGC () implants had significantly shorter surgery durations than the other three implants. One patient with a NexGen implant had a surgery duration of 210 minutes; a sensitivity analysis excluding this patient yielded similar omnibus results (), and the remaining NexGen implants still had a mean surgery duration of 113.3 (SD 15.3) minutes.
Tourniquet was used with the LCS more often than with the other implants ().
On the night of the surgery, hemoglobin values did not differ by implant type. However, on postoperative Day 4, the more common implants (Sigma and AGC) were associated with higher hemoglobin values than the other implants ().